Method of and apparatus for mounting die teeth



y 19, 3 'J.M..IY(IZRAYIGO I 1,806,147

METHOD OF AND APPARATUS FOR MOUNTING-DIE TEETH Filed April 24', 1929- Zlnowntor Lia/222M Crayo Patented May 19, 1931 hStldid? if H1? M. CRAIGO, OF HARTFORD, CONNECTICUT Application. file-cl April 24, 1829. Serial No. 357,731.

In the art of dentistry, it is the general practice, in making members adapted to be applied to teeth, (for example, members-such as crowns and matrices for inlays) to provide a die tooth which is a replica of that-to which the member is adapted to be attached, then form a female die by taking an impression of the die tooth, and, then swage the member between the cooperating dies. It

has been the practice to first mount the die tooth on an element, such as a plate or the like, and, in this operation, the positioning of the die tooth was determined in a hit-ormiss manner; that is, the dentist would tilt the tooth from one side to the other until he thought the tooth was in proper relation to the line of movement of the member in which the female die was to be formed. This hit-on miss practice was and is unsatisfactory, as

- not infrequently the tooth will lean to one side or the other, as the casev may be, to such an extent that an imperfect female dieis obtained.

The aim of the present invention is to provide a new method of procedure and a new mechanism by means of which the die tooth may be so mounted that it will be in the proper relation to the line on which the material in which the female die 'is to be formed is moved during the taking of the impression. By proceeding in accordance with the present invention, the die tooth may be very quickly and accurately mounted with the assurance that a more perfect and complete female die may be obtained therefrom.

In the accompanying drawin s, wherein there is shown, for illustrative purposes, only one embodiment of my invention;

Figure 1 is a front view of the machine with the parts shown in the act of paralleling the die tooth;

Fig. 2 is a view showing the die tooth as having been raised after it has been paralleled;

Fig. 3 is a view showing the parts in the act of securing the die tooth in its paralleled position upon a plate;

Fig. 4c discloses a femaledie as having been formed by taking an impression of the male die; and

Fig. 5 in place.

Referring to the drawings in detail, there is shown a machine which may be used in carrying out my improved method, it being obvious, however, that the steps of the present invention could be carried out in other machines. The machine may have a member on which the die tooth is adapted to be supported and a member movable on a straight line towards and away from the supporting member. In the present illustrative disclosure, the supporting member is shown as being in the form of a post 8 located on the base 10 of a machine frame. The reciprocating member is in'the form of a plunger 9 which isvertically movable in the headll carried by a standard 12 arising from the base 10.' The plunger may be is a top viewof the die tooth secured raised and lowered in any suitable manner,

as by means of pinion 13 meshing with a rack 14: on the plunger. The pinion may be turned by means of a handle 15.

For the purpose of holding the plate on which the die tooth is to be anchored, the support 8'may be provided with a pair of spring arms 16. r The plate to which the die is adapted to be secured is shown in cross section in Figs. 3 and 4: and is designated by thenumeral 17. This plate has, on its upper 'face, a rib 18 for confining the metal in which the tooth is adapted to be anchored. The plate also has an opening 19 through which this metal is adapted to flow. In each side edge of the plate is a notch 20, and these notches are adapted to receive the upper ends of the arms 16 so that the plate is properly positioned upon the post 8.

The paralleling device may include a stem secured for turning movement in the lower end of the plunger 9 by means of a screw 26. Carried by the stem 25, for transverse movement, is a U-shaped slide 27 to the upper arm of which is pivoted, as at 28, a paralleling tool 29 having a vertical straight edge 30. The lower arm of the slide has a shoulder 31 against which the paralleling tool is adapted to engage when the latter isin itswroking position; that is, when the straight edge is parallel to the line of movement of the plunger 9. The member 27 is slidably car ried by the stem 25 so that it maybe moved out of the way, as shown in Figs. 2 and 3, and the tool 29 may be pivoted to the slide so that, if desired, it can be swung further out of the way, as shown in Fig. 3.

, By way of illustration, I have shown a die tooth T on which an inlay is adapted to be swaged. This die tooth has a groove across its top and down opposite sides. The side walls of this groove are parallel to each other.

The bottom walls of the grooves in the side faces of the tooth are parallel to each other and to the axis of the tooth. Obviously, this die tooth is shown by way of exemplification only and my improved method may be carried out for swaging full crowns, threequarter crowns and other appliances.

' Having described, for purposes of illustration, various elements which may be employed for carrying out my improved method, the method will now be described in detail. The die tooth, designated by the letter T, is positioned upon a small body of yielding, but 11011-T8Sill611t, material 50, such as wax, which, when given any shape, will maintain that shape. The straight edge 30 is then brought into engagement with those portions of the tooth to be paralleled. For example, the straight edge may be engaged with the bottom of one of the side grooves in the die tooth, and the tooth may be moved or tilted on the wax until the bottom wall of that groove is parallel to the straight edge 30, which means'that it is parallel to the line of movement of the plunger 9. Also, the tooth may be adjusted on the waxso as to insure that the sidewalls of the grooves are parallel to the straightedge and to the line of movement of the plunger 9. The stem 25 may be turned about its axis so. as to bring the straight edge into engagement with various portlons of thetooth. The tooth now having been paralleled, it Will retain 1ts parallel position upon the wax 50 and the paralleling tool 29 will be moved out of the way, that is to the position shown in either Fig. 2 or 3.

Then, a small body or wad of a gum or sticky wax 51 is applied to the lower end of the stem 25. This gum or wax is also yielding but non-resilient. The plunger is now lowered so as to bring the gum 51 against the top of the tooth and then the plunger is raised with the die tooth sticking to thelower end of the stem 25. In this operation, the paralleled position of the die tooth is not disturbed; that is, it maintains the same relation to the line of movement of the plunger. The plate 17 may now be positioned upon the support 8, as shown in Fig. 3, and a hot metal 52 poured into the rib 18. Then the plunger is lowered so that the lower end or base of the tooth will extendinto this metal, the latter then being allowed to harden with the result that thetooth isanchored therein. In bringing the die tooth down into the metal 52, it is moved on the line of movement of the plunger and its relation to that line is not disturbed. The die tooth is now secured to the plate in such position that an impression may be taken thereof.

The paralleling device is now' removed from the plunger and a die carrying element 53 substituted therefor. This element has a recess 5 l in its lower end adapted to receive a body 55 of mold-inc or other material in which the female die is to be formed. plunger is now lowered, thereby taking an impression in the material 55 so that a female die ishad which is the exact counterpart of the male die. It will be observed that, since the male die has been properly paralleled with respect to the line of movement of the female die, as complete and as accurate a female die is obtained as is possible and, particularly, the female die'will be pro vided with a rib corresponding to the U shaped groove with which the male die is provided. The female die now having been accordance with the present invention, the

male die may be very accurately and quickly brought to a position which will insure a correct and accurate female die, and the objections to the old hit-or-miss practice are to a large extent removed.

As many changes could be made in the above construction and many apparently widely. different embodiments of thisinvention could be made without departing from the scope thereof, it is intended that all matter contained in the above description, or shownin the accompanying drawing, shall be interpreted as illustrative and not in a limiting sense. 7

It is also to be understood that the language used in the following claims is intended to cover all of thegeneric and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. The herein described methodwhich consists in positioning a tooth element upon a body of yielding, non-resilient material, then paralleling said element into predetermined alignment with a given line, then raising the tooth element on said line without disturbing its relation thereto, substituting for said body of yielding material a member to which said tooth element. is to be anchored, and then moving said tooth element on saidline into anchoring relation to said member.

The

2. Theherein described method which consists in positioning a toot-h element upon a 7 line without disturbing its relation thereto,

substituting for said body a member to which said element is to be anchored, and then moving said element on said line into anchoring relation to said member.

3. The herein described method which consists in positioning a tooth element upon a body of yielding, non-resilient material, then paralleling the element into predetermined alignment with agiven line, applying to a member movable on said line a sticky yielding and non-resilient material, moving said member on said line to bring said sticky material into engagement with said element and then moving said member with the element stuck thereon away from said body, then substituting for said body a device to which said element is to be anchored, and then moving said member to bring said element into anchoring relation to said device.

4. The herein described method which consists in positioning a die tooth upon a body of yielding non-resilient material, paralleling the tooth into predetermined alignment with a given line by means of a straight edge parallel to said line, applying to a member movable on said line a sticky yielding nonresilient material, moving said member on said line towards said tooth'so as to bring said sticky material into engagement with the latter, then raising said member with the tooth stuck thereon on said line and Without disturbing the paralleled relation of said tooth, then substituting .for said body of member movable on said line a sticky yielding non-resilient material, moving said mem her on said line to bring said sticky material into engagement with said tooth, then moving said member with the tooth stuck thereon away from said body, then substituting for said body a device to which said tooth is adapted tobe anchored, then moving said member with the tooth stuck thereon into an choring relation to said device, then substituting said member for a die element carrying a material in which an impression is to be taken, and then moving said die element towards said tooth on said line to take said impression.

7. In a machine of the character described, a support, a plunger movable towards and away from said support, a stem carried by said plunger, a slide carried by said stem for sliding movement at right angles to the line of movement of said plunger, and a parallel ing tool carried by said slide, said tool having a straight edge which is parallel to the line of movement of said plunger when the tool is in operative position and said straight edge being positioned beyond the end of said plunger for engagement with an article carried by said support.

8. In a machine of the character described, a paralleling device including a stem, a U- shaped slidehaving a pair of arms extending through said stem, paralleling tool pivoted to one of said arms and having a straight edge, and a shoulder on the other of said arms and against which said tool is adapted to engage when in operative position, said straight edge being in parallelism with said stem and positioned beyond the end of said stem when said tool is in operative position.

JOHN M. CRAIGO.

yielding material adevice to which said tooth is adapted to be anchored, and then lowering said member to bring the tooth stuck thereon into anchoring relation to said device.

5. The herein described method which consists in positioning a die tooth upon a body of yielding non-resilient material, then paralleling the tooth into predetermined alignment with a given line, then raising the tooth on i said line without disturbing its parallel relation, substituting for said body a device to which said tooth is to be anchored, moving said tooth on said line into anchoring relation to said device, and then taking an impression of said tooth element.

6. The herein described method which consists in positioning a die tooth upon a body of yielding non-resilient material, then paralleling said tooth into predetermined alignment with a given line, then applying to a 

